The effect of zinc and melatonin supplementation on immunity parameters in breast cancer induced by DMBA in rats

Melatonin: Current evidence on protective and therapeutic roles in gynecological diseases

Melatonin, a potent antioxidant and free radical scavenger, has been demonstrated to be effective in gynecological conditions and female reproductive cancers. This review consolidates the accumulating evidence on melatonin's multifaceted protective effects in different pathological contexts. In gynecological conditions such as endometriosis, polycystic ovary syndrome (PCOS), and uterine leiomyoma, melatonin has shown promising effects in reducing oxidative stress, inflammation, and hormonal imbalances. It inhibits adhesion molecules' production, and potentially mitigates leukocyte adherence and inflammatory responses. Melatonin's regulatory effects on hormone production and insulin sensitivity in PCOS individuals make it a promising candidate for improving oocyte quality and menstrual irregularities. Moreover, melatonin exhibits significant antitumor effects by modulating various signaling pathways, promoting apoptosis, and suppressing metastasis in breast cancers and gynecological cancers, including ovarian, endometrial, and cervical cancers. Furthermore, melatonin's protective effects are suggested to be mediated by interactions with its receptors, estrogen receptors and other nuclear receptors. The regulation of clock-related genes and circadian clock systems may also contribute to its inhibitory effects on cancer cell growth. However, more comprehensive research is warranted to fully elucidate the underlying molecular mechanisms and establish melatonin as a potential therapeutic agent for these conditions.

Chemopreventive potential of hydroethanolic Murraya koenigii leaves extract against DMBA induced breast carcinogenesis: In-silico and in-vivo study

ETHNOPHARMACOLOGICAL RELEVANCE

Murraya koenigii (MK), a member of the Rutaceae family and widely known as the curry-leaf tree, is indigenous to India, Sri Lanka, and other south Asian nations. It is a renowned medicinal herb because of the wide range of bioactive components found in its leaves, such as girinimbine, koenimbine, mahanimbine and mahanine among others. All these bioactive components make this plant beneficial for treating a variety of ailments and diseases. Biological and pharmacological activities of MK include anti-oxidant, anti-microbial, anti-ulcer, anti-helminthic, anti-malarial, anti-trichomonal, hepatoprotective, anti-diabetic, etc. AIM OF THE STUDY: The present study aimed to evaluate the possible protective effect of hydroethanolic Murraya koenigii leaves extract (HEMKLE) against 7,12-Dimethylbenz[a]anthracene (DMBA)-induced breast cancer in rats, which further paves the way for future breast cancer treatment.

MATERIALS AND METHODS

For the preparation of hydroethanolic Murraya koenigii leaves extract (HEMKLE), Murraya koenigii (MK) leaves were taken from the botanical garden of the Panjab University campus, Chandigarh, and authenticated from the Department of Botany, Panjab University (accession number 22417). The phytochemical characterization of HEMKLE was performed using liquid chromatography-mass spectrometry (LC-MS). Following this, an in-silico molecular docking analysis was performed using Maestro Schrodinger software, and an in-vivo study was conducted. For the in-vivo study, female SD rats were divided into four different groups. Group I (C), Group II (DMBA), Group III (HEMKLE), and Group IV (HEMKLE + DMBA). Histopathogy, oxidative and antioxidant status, immunohistochemistry of estrogen receptor-α, TUNEL assays, mRNA and protein expression of apoptotic pathway genes were conducted in in-vivo study.

RESULTS

In LC-MS, major phytochemical constituents including flavonoids and carbazole alkaloids were identified. In-silico docking study revealed the strong binding affinity between the identified compounds with caspase-3. Additionally, koenine displayed the highest binding affinity/minimum energy of -9.21 kcal/mol with 6BDV as compared to other phytochemicals. Furthermore, in-vivo experimentation revealed that HEMKLE administration in Group IV(HEMKLE + DMBA) significantly inhibits the tumor incidence and volume as compared to alone DMBA treated group. The antioxidant action of HEMKLE was proven from the in-vivo analysis of antioxidant marker enzymes, histopathology, immunohistochemistry of ER-α studies. Further, increase number of TUNEL positive cells was observed in co-treated animals as compared to alone DMBA treated animals. In Group IV (HEMKLE + DMBA), upregulated expression of pro-apoptotic genes and downregulated expression of anti-apoptotic gene were observed when compared to Group II(DMBA) suggested the apoptotic effect of HEMKLE.

CONCLUSION

The results of the present study provide clear evidence of the chemopreventive capabilities of HEMKLE in rats with DMBA-induced breast cancer. The observed outcomes could potentially be attributed to the existence of diverse phytochemicals within the HEMKLE.

Association of Dietary Intake of Zinc and Selenium with Breast Cancer Risk: A Case-Control Study in Chinese Women

As major nonenzymatic antioxidant components in the body, dietary Zinc (Zn) and Selenium (Se) may have an impact on breast cancer development. This study aimed to investigate the relationship between dietary Zn, Se intake and breast cancer risk in Chinese women. The case-control study included 1591 cases and 1622 age-frequency matched controls. Dietary intake was collected using a validated food frequency questionnaire. Dietary Zn and Se were divided into four categories: Zn/Se from plants, Zn/Se from meat, Zn/Se from red meat, and Zn/Se from white meat. Unconditional logistic regression models and restricted cubic spline analyses were performed to identify potential associations. Zn from white meat intake was linearly and inversely associated with breast cancer risk, and Se from red meat intake was linearly and positively associated with breast cancer risk, with adjusted odds ratio and 95% confidence interval of 0.76 (0.61-0.95) and 1.36 (1.04-1.77), respectively. Non-linear relationships were found between total dietary Zn, Zn from meat, Zn from red meat intake and breast cancer risk (p_{non-linearity} < 0.05). In conclusion, dietary Zn and Se intake were associated with breast cancer risk in Chinese women, and the optimal intake of Zn may be beneficial for breast cancer prevention.

Role of Combination Treatment of Aspirin and Zinc in DMH-DSS-induced Colon Inflammation, Oxidative Stress and Tumour Progression in Male BALB/c Mice

Colitis-associated colorectal cancer serves as a prototype of inflammation-associated cancers which is linked with repeated cycles of inflammation and DNA repair deficits. Several preclinical and clinical data reported that aspirin has a chemo-preventive effect in colorectal cancer and is associated with dose-dependent side effects. Furthermore, it has been reported that zinc supplementation improves the quality of life in patients undergoing chemotherapy by alteration of colonic cancer cell gene expression. However, explication of the detailed molecular mechanisms involved in the combined administration of aspirin and zinc-mediated protection against colitis-associated colorectal cancer deserves further investigation. For the induction of colitis-associated colorectal cancer, male BALB/c mice were administered 1,2-dimethylhydrazine dihydrochloride (DMH) 20 mg/kg/bw thrice before the initiation of every DSS cycle (3%w/v in drinking water). One week after the initiation of DSS treatment, aspirin (40 mg/kg; p.o.) and zinc in the form of zinc sulphate (3 mg/kg; p.o.) were administered for 8 weeks. Combination of aspirin and zinc as intervention significantly ameliorated DAI score, myeloperoxidase activity, histological score, apoptotic cells and protein expression of various inflammatory markers including nuclear factor kappa light chain enhancer of activated B cells (NFκBp65), cycloxygenase-2 (COX-2) and interleukin-6 (IL-6); proliferation markers such as proliferating cell nuclear antigen (PCNA), signal transducer and activator of transcription 3 (STAT3) expression significantly decreased, and antioxidant enzymes nuclear factor erythroid 2-related factor 2 (Nrf-2), metallothionein, catalase and superoxide dismutase (SOD) significantly increased as evaluated by immunohistochemistry and western blot analysis.

Dietary Trace Element Intake and Risk of Breast Cancer: A Mini Review

Trace elements are essentially required for various physiological and metabolic functions, and any disturbance in the trace elements homeostasis may result in the development of chronic diseases including breast cancer. Breast cancer is the most prevalent cancer type reported in women equally affecting both the high-income and low-income countries. This review therefore aimed to evaluate the impact of dietary trace element intake in relation to the incidence of breast cancer. We focused on five trace elements, thus emphasizing dietary selenium, zinc, iron, copper, and cadmium intake and risk of breast cancer. A systematic approach was applied to perform this review through entering a search term in PubMed and Scopus databases. A total of 24 articles were included after meeting the inclusion and exclusion criteria. Most of the studies regarding dietary iron intake showed a detrimental effect of increased dietary heme iron on breast cancer incidence risk. In addition, there is a limited evidence of high dietary intake of selenium and zinc to reduce the risk of breast cancer. Also, a few studies showed a relationship between high cadmium consumption and risk of breast cancer. More studies related to cadmium and copper exposure are needed to confirm this relationship. As a result, the findings of this review suggested that high dietary heme iron is a potential risk factor for breast cancer.

The Combination of Zinc and Melatonin Enhanced Neuroprotection and Attenuated Neuropathy in Oxaliplatin-Induced Neurotoxicity

Objective

The present study was designed to investigate the possible synergistic effects of melatonin with zinc in the prevention and treatment of oxaliplatin-induced neurotoxicity in rats.

Methodology

Forty-eight male Wistar albino rats were used and randomly allocated into six groups: The negative control group, oxaliplatin group, zinc + oxaliplatin group, melatonin + oxaliplatin group, zinc + melatonin + oxaliplatin prevention-approach group, and zinc + melatonin + oxaliplatin treatment-approach group. The thermal nociceptive/hyperalgesia tests were performed. Brain tissue homogenate was used for measuring GFAP, NCAM, TNF α, MAPK 14, NF-kB, GPX, and SOD. Brain tissue was sent for histopathological and immunohistochemistry studies.

Results

The combination therapies showed improvement in the behavioral tests. A significant increase in GPX and SOD with a significant decrease in GFAP levels resulted in the prevention approach. TNF α decreased significantly in the treatment approach. No significant changes were seen in NCAM, NFkB, and MAPK-14. The histopathological findings support the biochemical results. Additionally, immunohistochemistry revealed a significant attenuation of p53 and a non-significant decrease in Bcl2 levels in the combination groups.

Conclusion

The combination of zinc with melatonin for the prevention approach was effective in attenuating neurotoxicity induced by oxaliplatin. The proposed mechanisms are boosting the antioxidant system and attenuating the expression of p53, GFAP, and TNF-α.

Chronic Running Exercise Regulates Cytotoxic Cell Functions and Zinc Transporter SLC39A10/ZIP10 Levels in Diabetic Rats

The aim of this study is to investigate how chronic running exercise affects ZIP10 levels in thymus and spleen tissue as well as immune parameters in diabetic rats. A total of 40 adult male Wistar rats were divided into 4 equal groups: group 1, control; group 2, exercise control; group 3, diabetes; group 4, diabetes + exercise. Diabetes was induced by injecting intraperitoneal streptozotocin (STZ) at a dose of 40 mg/kg twice with 24-h intervals to the animals in groups 3 and 4. The animals in group 2 and group 4 underwent exercise for 45 min on the rat treadmill for 4 weeks at 20 m/min. Twenty-four hours after the last running exercise, the animals were sacrificed under general anesthesia. Immunological parameters were determined by flow cytometric method; tissue ZIP 10 levels were determined by ELISA method. The diabetic group had the lowest natural killer (NK) and natural killer T (NKT) cells percentages. Chronic exercise partially improved NK and NKT cell percentages in diabetic rats. The diabetic group had the lowest ZIP10 levels in spleen and thymus tissue. ZIP10 values in spleen and thymus tissue of diabetes exercise group were significantly higher than diabetes group. The results of our study show that the impaired cytotoxic cell functions in diabetes are partially corrected with 4 weeks of chronic exercise, and that the suppressed ZIP 10 levels in diabetic rats are reversed by 4 weeks of chronic exercise.

Supplementation With Vitamin E, Zinc, Selenium, and Copper Re-Establishes T-Cell Function and Improves Motor Recovery in a Rat Model of Spinal Cord Injury

Spinal cord injury (SCI) causes a dysfunction of sympathetic nervous system innervation that affects the immune system, leading to immunosuppression syndrome (ISS) and contributing to patient degeneration and increased risk of several infections. A possible therapeutic strategy that could avoid further patient deterioration is the supplementation with Vitamin E or trace elements, such as Zinc, Selenium, and Copper, which individually promotes T-cell differentiation and proliferative responses. For this reason, the aim of the present study was to evaluate whether Vitamin E, Zinc, Selenium, and Copper supplementation preserves the number of T-lymphocytes and improves their proliferative function after traumatic SCI. Sprague–Dawley female rats were subjected to moderate SCI and then randomly allocated into three groups: (1) SCI + supplements; (2) SCI + vehicle (olive oil and phosphate-buffered saline); and (3) sham-operated rats. In all rats, the intervention was initiated 15 min after SCI and then administered daily until the end of study. Locomotor recovery was assessed at 7 and 15 days after SCI. At 15 days after supplementation, the quantification of the number of T-cells and its proliferation function were examined. Our results showed that the SCI + supplements group presented a significant improvement in motor recovery at 7 and 15 days after SCI. In addition, this group showed a better T-cell number and proliferation rate than that observed in the group with SCI + vehicle. Our findings suggest that Vitamin E, Zinc, Selenium, and Copper supplementation could be part of a therapy for patients suffering from acute SCI, helping to preserve T-cell function, avoiding complications, and promoting a better motor recovery. All procedures were approved by the Animal Bioethics and Welfare Committee (Approval No. 201870; CSNBTBIBAJ 090812960).

Protective Effects of Antioxidant Chlorophyllin in Chemically Induced Breast Cancer Model In vivo

Glutathione-related enzymes belong to the protection mechanism of the cells against harmful oxidative damage and chemicals. Glutathione S-transferase (GST) is frequently over-expressed in various cancer cells and is involved in drug resistance. Chlorophyllin is an antioxidant molecule interfering with the GST P1-1 activity. The purpose of this study is to evaluate the short- and long-term protective effects of chlorophyllin as an antioxidant molecule on DNA damage, antioxidant enzyme activities, trace elements, and minerals in chemically induced breast cancer model in vivo. In our study, N-methyl-N-nitrosourea (MNU) was used for inducing breast carcinogenesis in female Sprague-Dawley rats. A total of 36 rats were divided into groups as short term and long term. Each group was divided into four sub-groups as control group received physiological saline solution (n = 3), Chl group (n = 5) received chlorophyllin, MNU group (n = 5) was administered MNU, and Chl + MNU group (n = 5) was treated with both chlorophyllin and MNU. Results illustrated that chlorophyllin had a significant anti-genotoxic effect in the short term, and glutathione-related enzyme activities were protected by chlorophyllin treatment in MNU-induced breast cancer model. Additionally, MNU administration impaired mineral and trace element levels including Na, Mg, K, Fe, Zn, and Co in the liver, kidney, spleen, heart, and tumor tissues; however, adverse effects of MNU were recovered upon chlorophyllin treatment in the indicated tissues of the rats. In conclusion, chlorophyllin can be used as an antioxidant molecule to ameliorate adverse effects of MNU by enhancing antioxidant enzyme activities and regulating trace element and mineral balance in several organs and tumor tissue in the breast cancer model.

Is molluscum contagiosum related to zinc deficiency in children? Effectiveness of oral zinc sulfate therapy in lesion regression

OBJECTIVES

Molluscum contagiosum (MC) is viral skin infection that is most commonly observed in children. Zinc homeostasis is essential for proper immune function, especially in host-virus interactions. This study aimed to investigate the effectiveness of oral zinc sulfate treatment in children with MC.

METHODS

The subjects included 23 children with MC and 30 age/sex-matched healthy children as controls. Children with MC received oral zinc sulfate for 2 mo, and serum zinc levels were measured before and after the treatment period. Patients were examined every 4 wk for evidence of partial or complete lesion regression. Lesion numbers were recorded before treatment and during follow up.

RESULTS

The mean serum zinc levels in children with MC did not differ from those in controls (80.57 ± 10.14 vs 81.90 ± 8.47 μg/dL, respectively, P = 0.370). After zinc sulfate supplementation, the mean serum zinc levels increased from 80.57 ± 10.14 to 100.5 ± 9.95 μg/dL (P < 0.001) in subjects with MC. After a 2-mo treatment period, six subjects exhibited resolution of lesions at the 1-mo follow up, 10 subjects at the 2-mo follow-up, and three subjects at the 3-mo follow up. Disease recurrence was not observed. A 6-y-old boy and two 4-y-old girls without other systemic symptoms had MC lesions that persisted after zinc sulfate therapy and throughout the 1-y follow up. One female subject experienced complete recovery in after treatment month 4, but recurrence was observed in month 7 and persisted for 18 mo.

CONCLUSIONS

Our findings support the use of oral zinc sulfate as a therapy for children with MC.

Effect of zinc supplementation on mortality in under 5-year children: a systematic review and meta-analysis of randomized clinical trials

BACKGROUND

Several clinical trials evaluated the effect of zinc supplementation on mortality in children, but the results were inconsistent. We aimed to conduct a systematic review and meta-analysis on the impact of zinc supplementation on mortality in under 5-year children.

METHODS

A comprehensive search was conducted using the electronic (PubMed, Scopus, Web of Science) databases, and Google Scholar, up to June 2020. Randomized clinical trials (RCTs) that reported the effect of zinc supplementation on death incidence in under 5-year children were included in the analysis. Screening was performed based on title/abstract and full-text. A random effects model was applied to calculate the summary relative risk (SRR). Risk of Bias 2.0 tool was used to rate the quality of trials. The body of evidence was assessed by the GRADE approach.

RESULTS

Combining 30 RRs from 28 RCTs including 237,068 participants revealed that zinc supplementation has significantly reduced the risk of all-causes mortality by 16% in children (SRR: 0.84, 95% CI: 0.74, 0.96). A follow-up duration of less than 1 year after supplementation resulted in 54% reduced risk of mortality (0.46; 0.33, 0.63) with no heterogeneity between investigations. Subgroup analysis by zinc dosage showed that assigning ≥ 10 mg/d zinc to under five children and duration of less than 11 months of intervention decreased the risk of all-cause mortality by 44% (0.56; 0.42, 0.75) and 48% (0.52; 0.38, 0.72), respectively. In low birth weight (LBW) infants, zinc supplementation was reduced all-cause mortality by 52% (0.48; 0.23, 1.00). Zinc supplementation significantly reduced the risk of death from pneumonia (0.70: 0.64, 0.98) and infection (0.54; 0.39, 0.76), also changed the risk of mortality from diarrhea by 15% (0.85; 0.70, 1.03) and sepsis by 57% (0.43; 0.18, 1.02).

CONCLUSION

This meta-analysis on RCTs revealed that zinc supplementation in under 5-year children has significantly reduced the risk of all-cause mortality. Notable decreases were found in trials with a dose of 10 mg/d or more zinc supplementation, a maximum of 11 months of supplementation, a follow-up less than one year and especially in LBW infants.

Zinc is a strong stimulant of metallothionein synthesis in the ischaemic testis tissue

This study was performed to determine the effect of zinc supplementation effects on metallothionein levels in testis ischaemia-reperfusion of rats. The experimental groups were designed as Control, Sham, Ischaemia-Reperfusion (I/R) and I/R + Zinc supplemented. Zinc supplemented as 5 mg/kg day for 3 weeks. Testis tissues were analysed for metallothionein by immunohistochemical staining procedures. Group comparison showed that the zinc-supplemented ischaemia-reperfusion group had a significantly higher level of cells strongly stained with metallothionein than all other groups. A general evaluation of the results suggests that zinc supplementation is a strong stimulant of metallothionein synthesis in the ischaemic testis tissue.

The Effect of Zinc and Melatonin Administration on Lipid Peroxidation, IL-6 Levels, and Element Metabolism in DMBA-Induced Breast Cancer in Rats

The purpose of this study was to investigate the effects of zinc and melatonin administration on interleukin-6, lipid peroxidation parameters, and element metabolism in DMBA-induced breast cancer in female rats. A total of 42 recently weaned Wistar rats were divided into 5 groups as follows: control (group 1), DMBA control (group 2), DMBA + zinc (group 3), DMBA + melatonin (group 4), and DMBA + melatonin and zinc (group 5). Malondialdehyde (MDA) and glutathione (GSH) levels in breast tissue and blood samples were determined via spectrophotometric methods. In addition, iron, magnesium, zinc, and copper levels in serum samples were determined by atomic emission, and plasma interleukin-6 levels were determined by ELISA method. The highest tissue and plasma MDA and the lowest tissue and erythrocyte GSH levels found in the study were in group 2; the highest tissue and erythrocyte GSH levels and the lowest tissue and plasma MDA levels are in group 5 (P < 0.05). Iron, magnesium, and zinc levels of groups 3, 4, and 5 were higher than the DMBA group without administration (group 2), but the copper values were significantly lower (P < 0.05). The highest IL-6 levels were determined in group 2 while IL-6 levels in the DMBA group (G5) treated with combined melatonin and zinc were lower than all other breast cancer groups (P < 0.05). According to the findings obtained in this presented study, combined zinc and melatonin therapy can contribute to the prevention of tumor growth by improving the disruption in element metabolism and suppressing IL-6 levels and reducing tissue damage that causes the cancer.

Effect of pinealectomy and melatonin supplementation on metallothionein, ZnT2, ZIP2, ZIP4 and zinc levels in rat small intestine

We investigated the relations among levels of metallothionein (MT); zinc (Zn) transport proteins, ZnT2, ZIP2 (ZRT and IRT-like proteins); and ZIP4, which enable Zn absorption in the small intestine of rats. We also investigated tissue Zn levels in the small intestine. We used four groups of adult male rats: group 1, control; group 2, pinealectomy (Px); group 3, Px + melatonin (MEL); group 4, MEL only. Animals in groups 3 and 4 were administered 5 mg/kg/day MEL for four weeks. At the end of the study, all animals were sacrificed and samples of duodenum, jejunum and ileum were harvested to analyze ZnT2, ZIP2, ZIP4 and MT levels using immunohistochemistry, and tissue Zn levels were measured by atomic absorption spectrophotometry. The lowest ZnT2 levels in the duodenum, jejunum and ileum, and the lowest ZIP2 levels in the duodenum and ileum were found in group 2. The lowest ZIP4 levels were found in the duodenum and jejunum, and the lowest MT levels in the duodenum and ileum were found in group 2. The highest MT values in the ileum were found in group 4. We found that ZnT2, ZIP2, ZIP4 and MT levels were reduced in the ileum compared to controls following Px, but levels approached control values after MEL administration. By its effects on ZnT2, ZIP2, ZIP4 and MT levels, MEL participates in the absorption of Zn in the rat small intestine.

Potential health benefits of zinc supplementation for the management of COVID-19 pandemic

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the etiological agent for the Coronavirus Disease 2019 (COVID-19). The COVID-19 pandemic has created unimaginable and unprecedented global health crisis. Since the outbreak of COVID-19, millions of dollars have been spent, hospitalization overstretched with increasing morbidity and mortality. All these have resulted in unprecedented global economic catastrophe. Several drugs and vaccines are currently being evaluated, tested, and administered in the frantic efforts to stem the dire consequences of COVID-19 with varying degrees of successes. Zinc possesses potential health benefits against COVID-19 pandemic by improving immune response, minimizing infection and inflammation, preventing lung injury, inhibiting viral replication through the interference of the viral genome transcription, protein translation, attachment, and host infectivity. However, this review focuses on the various mechanisms of action of zinc and its supplementation as adjuvant for vaccines an effective therapeutic regimen in the management of the ravaging COVID-19 pandemic. PRACTICAL APPLICATIONS: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiological agent for the Coronavirus Disease 2019 (COVID-19), has brought unprecedented untold hardship to both developing and developed countries. The global race for vaccine development against COVID-19 continues with success in sight with attendant increasing hospitalization, morbidity, and mortality. Available drugs with anti-inflammatory actions have become alternative to stem the tide of COVID-19 with attendant global financial crises. However, Zinc is known to modulate several physiological functions including intracellular signaling, enzyme function, gustation, and olfaction, as well as reproductive, skeletal, neuronal, and cardiovascular systems. Hence, achieving a significant therapeutic approach against COVID-19 could imply the use of zinc as a supplement together with available drugs and vaccines waiting for emergency authorization to win the battle of COVID-19. Together, it becomes innovative and creative to supplement zinc with currently available drugs and vaccines.

Melatonin: A Potential Therapeutic Option for Breast Cancer

Melatonin has significant inhibitory effects in numerous cancers, especially breast cancer. In estrogen receptor (ER)-positive human breast cancer, the oncostatic actions of melatonin are mainly achieved by suppressing ER mRNA expression and ER transcriptional activity via the MT1 receptor. Melatonin also regulates the transactivation of nuclear receptors, estrogen-metabolizing enzymes, and the expression of related genes. Furthermore, melatonin suppresses tumor aerobic glycolysis, critical cell-signaling pathways relevant to cell proliferation, survival, metastasis, and overcomes drug resistance. Studies in animal and human models indicate that disruption of the circadian nocturnal melatonin signal promotes the growth, metabolism, and signaling of human breast cancer, resulting in resistance to hormone therapy and chemotherapy, which may be reversed by melatonin.

Role of Zinc in Immune System and Anti-Cancer Defense Mechanisms

The human body cannot store zinc reserves, so a deficiency can arise relatively quickly, e.g., through an improper diet. Severe zinc deficiency is rare, but mild deficiencies are common around the world. Many epidemiological studies have shown a relationship between the zinc content in the diet and the risk of cancer. The anti-cancer effect of zinc is most often associated with its antioxidant properties. However, this is just one of many possibilities, including the influence of zinc on the immune system, transcription factors, cell differentiation and proliferation, DNA and RNA synthesis and repair, enzyme activation or inhibition, the regulation of cellular signaling, and the stabilization of the cell structure and membranes. This study presents selected issues regarding the current knowledge of anti-cancer mechanisms involving this element.

Manganese levels and hepatocellular carcinoma: A systematic review and meta-analysis based on Asian cohort

Several studies have investigated the relationship between Manganese (Mn) levels and hepatocellular carcinoma (HCC), but the results were inconsistent. Thus, we conducted a systematic review and meta-analysis to evaluate the association between Mn levels and HCC. Nine studies focusing on hair Mn levels, 6 studies on serum Mn levels and 6 studies on tissue Mn levels were identified in a systematic search of PubMed, CNKI, Wanfang and SinoMed databases. Standard mean differences (SMD) with the corresponding 95% confidence intervals (CI) were pooled to compare the Mn levels between HCC and controls. In serum, the Mn levels in HCC were significantly lower than in healthy controls (SMD (95% CI): -0.941 (-1.559, -0.323)). In hair, the Mn levels in HCC were slightly lower than in healthy controls, but not significant (SMD (95% CI): -0.168 (-0.766, 0.430)). In tissue, the Mn levels in tumors were significantly lower than in adjacent normal tissues (SMD (95% CI): -4.867 (-7.143, -2.592)). Subgroup analysis showed consistent results. In conclusion, this meta-analysis suggested an inverse association between Mn levels and HCC.

The Effect of Zinc Deficiency and Supplementation on Elements in the Kidney Tissue of Ovariectomized Rats: Histopathologic Changes

The objective of the present study is to determine the effects of zinc deficiency in and zinc supplementation to ovariectomized rats on some elements in kidney tissue. The study included 40 Sprague-Dawley type adult female rats. The experimental animals were randomized into four groups with equal numbers as follows: Group 1: Control (10). Group 2: Ovariectomized control (10). Group 3: Ovariectomized + zinc supplemented (10). Group 4: Ovariectomized + zinc deficient (10). After the animals were decapitated at the end of the experiment, element levels were determined by Atomic Emission (ICP-AES) as mg/g/wet tissue for calcium, phosphate, zinc, aluminum, copper, iron, lithium, and manganese and μg/g/wet tissue for magnesium in the kidney tissue. Additionally, the tissue samples were subjected to a histopathologic assessment. An examination of the study results showed that ovariectomy significantly reduced calcium, phosphorus, and zinc levels, while zinc supplementation to the rats following ovariectomy restored the reduced element levels to normal (0.10 ± 0.03, 0.85 ± 0.16, 0.11 ± 0.03 vs 0.19 ± 0.06, 1.86 ± 0.18, 0.52 ± 0.05). Group 4, which was both ovariectomized and fed on a zinc-deficient diet, had significantly lower aluminum, copper, and lithium values. Calcification, inflammation, and sclerotic changes in group 4, the group which was fed on a zinc-deficient diet, were greater in comparison to other groups (p < 0.05). Results of the study suggest that ovariectomy + zinc deficiency leads to calcification, inflammation, and sclerotic changes in renal tissue and significantly reduces element levels, whereas zinc supplementation after ovariectomy restores the lowered element levels to normal.

Role of immune-pineal axis in neurodegenerative diseases, unraveling novel hybrid dark hormone therapies

The anti-oxidant effects of melatonin and the immune-pineal axis are well established. However, how they play a role in the pathogenesis of neurodegenerative diseases is not well elucidated. A better understanding of this neuro-immuno-endocrinological link can help in the development of novel therapies with higher efficacy to alleviate symptomatology, slow disease progression and improve the quality of life. Recent studies have shown that the immune-pineal axis acts as an immunological buffer, neurohormonal switch and it also intricately links the pathogenesis of neurodegenerative diseases (like Multiple sclerosis, Alzheimer's disease, Parkinson's disease) and inflammation at a molecular level. Furthermore, alteration in circadian melatonin production is seen in neurodegenerative diseases. This review will summarise the mechanics by which the immune-pineal axis and neuro-immuno-endocrinological disturbances affect the pathogenesis and progression of neurodegenerative diseases. It will also explore, how this understanding will help in the development of novel hybrid melatonin hormone therapies for the treatment of neurodegenerative diseases.